CHAPTER 4 . Redox Processes in Anoxic Waters
Mn(IlM)
4
8
12
20
40
60
]:
80
1 100
~ 120
140
160
180
200
Fe (nM)
500
1000
1500
2000
20
40
60
]: 80
1 100
~ 120
140
160
180
200
16 0
2
0
Co (nM)
4
6
Pb(pM)
200
8
400
Fig. 4.13 b. Profiles of metals in the Framvaren Fjord: Mn, Co, Fe and Ph (Yao and Millero 1995h)
105
10
these differences could be caused by various sampling depth and/or fluctuation of Fe(II)
concentration with time. The lower value of 0.89 11M found in the winter might result from
the oxidation of Fe(II) near the interface by O 2 due to the enhanced water mixing in this
season. The concentrations of dissolved Fe(II) decreased rapidly below the maximum
to less than 40 nM in the bottom water, probably due to the formation of iron sulfides.
The concentration of phosphate in the surface water was about 0.4 11M and reached
a minimum (0.18 11M) between 16-18 m, which may be due to the high productivity at
this region or absorption onto Mn and Fe particles. The maximum values of particu-
Mn(IlM)
4
8
12
20
40
60
]:
80
1 100
~ 120
140
160
180
200
Fe (nM)
500
1000
1500
2000
20
40
60
]: 80
1 100
~ 120
140
160
180
200
16 0
2
0
Co (nM)
4
6
Pb(pM)
200
8
400
Fig. 4.13 b. Profiles of metals in the Framvaren Fjord: Mn, Co, Fe and Ph (Yao and Millero 1995h)
105
10
these differences could be caused by various sampling depth and/or fluctuation of Fe(II)
concentration with time. The lower value of 0.89 11M found in the winter might result from
the oxidation of Fe(II) near the interface by O 2 due to the enhanced water mixing in this
season. The concentrations of dissolved Fe(II) decreased rapidly below the maximum
to less than 40 nM in the bottom water, probably due to the formation of iron sulfides.
The concentration of phosphate in the surface water was about 0.4 11M and reached
a minimum (0.18 11M) between 16-18 m, which may be due to the high productivity at
this region or absorption onto Mn and Fe particles. The maximum values of particu-